1. Field of the Invention
The present invention relates to a suction roller system including a suction roller and a control head having a ventilation zone situated at a face side of the suction roller.
2. The Prior Art
A control head for controlling the suction stretch of a suction roller is known from the German patent DE 2 943 562 C2 and from the reference DE 10 2005 062 348 A1; the suction roller is mounted so as to rotate and rests, with one face side, against a face side of the control head having at least one control channel. The suction roller has at least one longitudinal channel that ends on the face side and extends coaxially to supply suction bores that extend crosswise to the roller surface with at least a partial vacuum.
In fast-running operation, the partial vacuum must be produced, and also canceled out again, very rapidly over the entire width of the suction roller, in each instance. In this connection, it can happen that the suction bores in the roller surface that are situated close to the opposite face side of the suction roller, which is usually closed, are not ventilated in timely manner, or ventilated only insufficiently by the control head. As a result, material residues in the region of the suction roller that lies opposite the control head remain adhered to it, and are not separated from the suction roller as desired, by ventilation of the suction roller.
A common alternative for solving this problem is to affix a second control head on the opposite face side of the suction roller, which is otherwise closed. This arrangement, however, is very cost-intensive. There is also insufficient space available in all suction roller systems for a second control head. Furthermore, the second suction head makes it more difficult to remove the suction roller, which is necessary for cleaning it.